Group II introns are found in the organellar genes of plants, fungi, and yeast and in the genomes of many bacteria. Group II introns have great promise as potential therapeutic agents and as model systems for the understanding folding, catalysis and molecular evolution. The pathway by which a group II intron folds into its active structure and catalyzes the variety of multi-step reactions involved in self-splicing is an intriguing unanswered question. The group II ribozymes also provide a valuable test of the generality of the folding characteristics that have been observed predominantly in Group I ribozymes. Preliminary studies are underway to determine the conditions under which synchrotron x-ray footprinting studies of the folding of a Group II ribozyme can be studied.